Quantum-Chemical Calculations of the Spectroscopic and Geometrical Parameters of CnF2n + 2 and CnF2n Fluorocarbons Full article
Journal |
Russian Journal of Physical Chemistry A
ISSN: 0036-0244 , E-ISSN: 1531-863X |
||||
---|---|---|---|---|---|
Output data | Year: 2005, Volume: 79, Number: 9, Pages: 1443-1450 Pages count : 8 | ||||
Tags | Fluorocarbons; Infrared spectroscopy; Olefins; Polymers; Polytetrafluoroethylenes; Quantum theory; Sensitivity analysis | ||||
Authors |
|
||||
Affiliations |
|
Abstract:
The DFT(B3LYP) (6-311+G(d) basis) and HF (6-31G basis) methods were used to calculate the geometric structure and vibrational spectra of the CnF2n + 2 and CnF2n (n = 3-13) conformers. An analysis of the results obtained demonstrated that starting from n = 5 the chain molecule has a structure of a zigzag chain (with bond lengths of R(C-C) = 1.53-1.54 angstrom and R(C-F) = 1.36-1.34 angstrom) twisted into a helix with a dihedral angle of 17 degrees. IR spectra were found to be sensitive to whether the CnF2n + 2 conformer is branched. This effect can be used to detect the formation of side -CF3 groups in polytetrafluoroethylene (PTFE). The 1783-1785-cm(-1) band in the spectrum of PTFE is indicative of the presence of terminal olefin groups in the structure of the polymer.
Cite:
Ignatʹeva L.N.
, Buznik V.M.
Quantum-Chemical Calculations of the Spectroscopic and Geometrical Parameters of CnF2n + 2 and CnF2n Fluorocarbons
Russian Journal of Physical Chemistry A. 2005. V.79. N9. P.1443-1450. WOS Scopus РИНЦ
Quantum-Chemical Calculations of the Spectroscopic and Geometrical Parameters of CnF2n + 2 and CnF2n Fluorocarbons
Russian Journal of Physical Chemistry A. 2005. V.79. N9. P.1443-1450. WOS Scopus РИНЦ
Original:
Игнатьева Л.Н.
, Бузник В.М.
Квантово-химические расчеты спектроскопических и геометрических параметров перфторуглеродов CnF2n + 2 и CnF2n
Журнал физической химии. 2005. Т.79. №9. С.1631-1638. RSCI РИНЦ
Квантово-химические расчеты спектроскопических и геометрических параметров перфторуглеродов CnF2n + 2 и CnF2n
Журнал физической химии. 2005. Т.79. №9. С.1631-1638. RSCI РИНЦ
Dates:
Submitted: | May 19, 2004 |
Published print: | Sep 1, 2005 |
Identifiers:
Web of science | WOS:000231615200015 |
Scopus | 2-s2.0-26244445767 |
Elibrary | 13480121 |
Chemical Abstracts | 2005:991121 |
Chemical Abstracts (print) | 144:128516 |